We are planning to 28VDC to 9V DC output with positive ON/OFF. There is a pin called PEN control. we are controlling PEN pin using NPN transistor.
The collector is connected to PEN pin and the emitter is connected to input supply ground(28V return).
What voltage should we apply on the base of the transistor?
What should be the ground reference for this input on base supply to switch on the transistor?
Can we drive the base pin using microcontroller which is powered on the output reference ground of DC DC convertor PTB78560C ?